预应力锚索边坡加固作用的离心机试验研究

Centrifuge experiment-based study on slope reinforcing effect of anchor cable

预应力锚索具有主动支护与被动支护的特点。预应力锚索施加初期,锚索预应力能够提高岩体整体性和破坏强度,有利于限制下部边坡开挖对上部边坡岩体的松弛卸荷影响作用,体现出了主动支护的作用。但是在边坡长期运行过程中,由于边坡岩体受外部应力产生的变形导致预应力锚索后期张拉受力,进而约束岩体变形发展,则体现出了被动支护。本研究利用离心机模型试验,对边坡中安装的锚索进行了运行过程中的受力分析,揭示了锚固边坡在运行过程中的预应力锚索支护作用发挥机理。研究结果对今后的岩质边坡支护设计具有重要的指导作用。

Prestressed anchor cable has the characteristics of taking both the active support and passive support into account. At the early stage of applying prestress to anchor cable, the prestress can enhance the integrity and failure strength of rock mass, and then is favorable to restrict the relaxing and unloading effects from the excavation of the lower part of slope on the rock mass of the upper part of slope, thus embodies the active supporting role. However, during the long-term operation of slope, the later-stage tensile stress is caused by the deformation brought about by both the unloading relaxation of the slope rock mass and the external stress, which embodies the passive supporting role. A stress analysis is made herein on the operation process of the anchor cable installed in slope with the centrifuge model experiment, and then the law of the exertion of the supporting role during the operation process of the prestressed anchor cable-supported slope is revealed as well. The study result has an important guiding role for the supporting design of rock slope in the days to come.